(a) Field of the Invention
The present invention relates to a plasma display panel (PDP), and more particularly, to a plasma display panel in which red (R), green (G), blue (B) unit pixels are arranged in a triangular configuration, or what is referred to as a delta arrangement.
(b) Description of the Related Art
A plasma display panel (PDP) is typically a display device in which ultraviolet rays generated by the discharge of gas excites phosphors to realize predetermined images. As a result of the high resolution possible with PDPs (even with large screen sizes), many believe that they will become a major, next generation flat panel display configuration.
The PDP is classified depending on how its discharge cells are arranged. The two main types of PDPs are the stripe PDP, in which spaces defined by barrier ribs and where gas discharge takes place are arranged in a stripe pattern(or in-line pattern); and the delta PDP, in which the discharge cells are arranged in a triangular (i.e., delta) shape.
In the conventional delta PDP, a plurality of R,G,B unit pixels are formed in a delta configuration between an upper substrate and a lower substrate. At locations corresponding to the positions of the discharge cells, sustain electrodes are formed on the upper substrate and address electrodes are formed on the lower substrate. The delta arrangement of the R,G,B unit pixels may be realized, for example, by closed barrier ribs formed in a triangular shape.
In such a delta PDP, an address voltage is applied between an address electrode and one of a pair of sustain electrodes that correspond to the selected unit pixel to thereby perform addressing, and a discharge sustain voltage is applied alternatingly to the pair of the sustain electrodes to thereby perform a sustaining operation. As a result, ultraviolet rays generated in the sustaining process excite phosphors in the discharge cell such that the phosphors emit visible light to thereby realize desired images. The PDPs disclosed in U.S. Pat. Nos. 5,182,489 and 6,373,195 are examples of such a delta PDP.
The above delta PDPs are realized not only through closed barrier ribs, but may be formed using a structure in which the linear barrier ribs for the stripe PDP are changed in shape. U.S. Pat. No. 6,376,986 discloses such a PDP. In this patent, the R,G,B unit pixels are formed into substantially hexagonal shapes by barrier ribs arranged in a meander formation.
In the PDPs mentioned above, the unit pixels are arranged in a triangular formation as described above such that when the R,G,B phosphors are grouped together to form one pixel, a width of one R,G,B unit pixel may be made approximately one-third larger than a pitch (horizontal pitch) of the pixel. Therefore, the high definition is superior to the PDP in which the unit pixels are formed in an in-line configuration, and the area of the non-illuminating regions in the screen is reduced to thereby improve luminance.
Although the conventional delta PDP has these advantages, in the delta PDPs disclosed up to this point, the characteristics of the unit pixels are not realized such that the overall characteristics of the delta PDP (e.g., luminance) are unable to be maximized, thereby providing difficulties when producing the actual PDP.
For example, in the PDP of U.S. Pat. No. 6,376,986, instead of forming the unit pixels in a closed configuration, the unit pixels are formed by barrier ribs in a meander formation in which the unit pixels are open in a column direction. This limits any attempt at maximizing the discharge space of the unit pixels.
Further, in the PDP of U.S. Pat. No. 5,182,489, the unit pixels are realized through closed barrier ribs, making conditions favorable for maximizing the size of the discharge cells. However, as far as the relation between an area of the discharge sustain electrodes provided within the pixels and the diffusion of discharge within the quadrilateral pixels is concerned, the length of the discharge sustain electrodes in the vertical direction is shorter than with the hexagonal pixels such that the diffusion of discharge at a center area is blocked substantially faster by the barrier ribs in the horizontal direction. Therefore, a reduction in luminance characteristics compared to the PDP using hexagonal pixels results.